ABSTRACT:The calculation of optimal driving strategies for on-board control of freight trains is a challenging task. In this talk we show how to calculate the critical switching points for a globally optimal strategy on a track with steep gradients using a new local energy minimization principle. The method has been implemented successfully in Australia where Pacific National uses the Freightmiser device to calculate optimal switching points and hence provide in-cab advice to train drivers on long-haul freight trains. We will also discuss a perturbation analysis to show how one might prove that the optimal switching points are uniquely defined. Joint work by Amie Albrecht, Phil Howlett, Peter Pudney and Xuan Vu.